PROJECT SUMMARY/ABSTRACT Adherence to antiretroviral therapy (ART) continues to present major challenges to HIV treatment and prevention. Adherence is a particularly challenging issue for adolescents, as seen by dramatically lower rates of adherence among adolescents compared to adults. Yet, adherence is especially vital for adolescents given that adherence can improve quality of life, delay progression towards AIDS, reduce risk for horizontal or vertical transmission, and limit proliferation of drug resistant HIV. The unique developmental transitions that occur during adolescence can pose both challenges and opportunities for adherence, suggesting the need for adolescent-centered interventions. Few behavioral interventions are specifically tailored by and for adolescents on ART. Adolescent-patient-centered conditional economic incentives (CEIs) have not yet been explored as an approach towards improving adherence behaviors among adolescents. The theoretical premise of this patient- centered and behavioral economic approach is that individual decision making often favors self-actualization but needs to contend with immediate gratification and discounted future outcomes. Patient-centered CEIs contingent on a behavior or outcome can alter this calculus by allowing recipients to experience immediate benefits of a positive health behavior rather than the weaker reward of improved health in the distant future. Adolescence is an ideal developmental timepoint to utilize CEIs since behavioral patterns are being developed. As such, short-term delivery of CEIs during a critical phase might be enough to start habituation of behaviors over the long term. Adherence is an ideal behavior for habituation. The adherence literature demonstrates that early-adolescent adherence to ART predicts long-term adherence. We propose a qualitative exploratory R21 study to investigate the acceptability of CEIs as an adolescent-centered approach for improving adherence in South Africa ? the country with the largest epidemic, and the largest number of HIV-positive adolescents. We propose the following specific aims: (1) to explore with HIV-positive adolescents acceptability and willingness to use CEIs using in-depth individual interviews including how to tailor CEIs to capitalize on adolescent developmental transitions including increased independence and responsibility; how the amount, format and frequency of CEIs may influence adherence; and how to enhance durability of adherence behavior with CEIs used as a stand-alone intervention or in combination with other interventions; (2) to explore perspectives from parents and HIV clinical providers on how family and clinic environments can enhance effects and durability of CEIs on adolescent adherence; and (3) to refine design for a future CEI intervention and optimize CEIs in combination with other promising interventions through user-centered intervention design development. We incorporate qualitatively identified preferences for CEIs (from Aims 1 and 2) into a computerized quantitative survey with conjoint analysis (Aim 3). Findings will advance HIV intervention science and clinical practice for HIV-positive young people who will have the potential to live longer and healthier lives.